Adhesive polyimide resin and adhesive laminate

Abstract

An adhesive polyimide resin which comprises a siloxane polyimide resin obtained from (A) an aromatic tetracarboxylic dianhydride and (B) a diamine ingredient comprising (B1) a diamine having a phenolic hydroxyl group, carboxyl group, or vinyl group as a crosslinkable reactive group and (B2) a siloxanediamine and has a glass transition temperature of 50 to 250□C and a Young's modulus (storage modulus) at 250□C of 10 5 Pa or higher; and a laminate which comprises a substrate comprising a conductor layer and an insulating supporting layer having at least one polyimide resin layer and, disposed on a surface of the substrate, an adhesive layer comprising a layer of the adhesive polyimide resin. The adhesive polyimide resin and the laminate have satisfactory adhesion strength even after exposure to a high temperature of up to 270□C and further have excellent heat resistance in reflow ovens. They are hence suitable for use in the bonding of electronic parts.

1. An adhesive polyimide resin comprising a siloxane polyimide resin obtained from (A) an aromatic tetracarboxylic dianhydride and (B) a diamine ingredient comprising (B1) a diamine having a crosslinkable reactive group and (B2) a siloxanediamine, said crosslinkable reactive group being a phenolic hydroxyl group, a carboxyl group or a vinyl group, and said adhesive polyimide resin having a glass transition temperature of from 50 to 250° C. and a Young's modulus (storage modulus) at 250° C. of 10 5  Pa or more. 
     
     
       2. The adhesive polyimide resin according to  claim 1 , which has a peel strength retention of 50% or more,
 wherein the peel strength retention is defined as a ratio (P 2 /P 1 ) of (A) the peel strength P 1  obtained by coating onto a substrate a siloxane polyimide precursor-containing resin solution in a stage prior to forming the adhesive polyimide resin, drying, heat-treating at 180° C. for 5 minutes, and thermocompression-bonding the resultant to an adherend, and (B) the peel strength P 2  obtained by thermocompression-bonding the resultant to an adherend after further heat-treating the resultant at 270° C. for 5 minutes.  
 
     
     
       3. A laminate which comprises a substrate having formed thereon a conductor, at least one layer of an insulating supporting layer and an adhesive polyimide resin layer, said insulating supporting layer having an average thermal expansion coefficient of 30×10 −6  or less, and said adhesive polyimide resin layer comprising a siloxane polyimide resin obtained from (A) an aromatic tetracarboxylic dianhydride and (B) a diamine ingredient comprising (B1) a diamine having a crosslinkable reactive group and (B2) a siloxanediamine, and said adhesive polyimide resin layer having a glass transition temperature of from 50 to 250° and a Young's modulus (storage modulus) at 250° C. of 10 5  Pa or more. 
     
     
       4. The laminate according to  claim 3 , wherein the laminate has bonded thereto at least one silicon chip through the adhesive polyimide resin layer on a bonding surface, the adhesive polyimide resin layer having a 90° peel strength between a surface of the silicon chip and the adhesive polyimide resin layer at room temperature of 0.8 kN/m or more at the bonding surface. 
     
     
       5. The laminate according to  claim 3 , wherein the polyimide resin of the insulating supporting layer has a multilayer structure comprised of a plurality of polyimide resin layers having different thermal expansion coefficients from each other, wherein a thickness ratio of the thickness (t 1 ) of a high thermal expansion resin layer having a thermal expansion coefficient of 30×10 −6  or more to the thickness (t 2 ) of a low thermal expansion resin layer having a thermal expansion coefficient of less than 20×10 −6  is in a range of 2<t 2 /t 1 <100, and wherein the high thermal expansion resin layer contacts the conductor. 
     
     
       6. A method of producing the laminate according to  claim 3 , comprising
 directly coating a polyimide precursor resin solution on a conductor to form at least one layer of a polyimide precursor resin on the conductor,  
 heat curing the polyimide precursor resin layer to form a conductor/polyimide laminate, then  
 coating an adhesive polyimide precursor resin solution on a polyimide surface of the laminate, and  
 heating it to obtain the laminate.  
 
     
     
       7. A polyimide resin which comprises a siloxane polyimide resin obtained from (A) an aromatic tetracarboxylic dianhydride and (B) a diamine ingredient comprising (B1) a diamine having a crosslinkable reactive group and (B2) a siloxanediamine, said crosslinkable reactive group being a phenolic hydroxyl group, a carboxyl group or a vinyl group, and said polyimide resin having a glass transition temperature of from 50 to 250° C. and a Young's modulus (storage modulus) at 250° C. of 10 5  Pa or higher. 
     
     
       8. A laminate which comprises a substrate having formed thereon a conductor, at least one layer of an insulating supporting layer and an adhesive polyimide resin layer, said insulating supporting layer having an average thermal expansion coefficient of 30×10 −6  or less, and said adhesive polyimide resin layer comprising a siloxane polyimide resin obtained from (A) an aromatic tetracarboxylic dianhydride and (B) a diamine ingredient comprising (B1) a diamine having a crosslinkable reactive group and (B2) a siloxanediamine, said crosslinkable reactive group being a phenolic hydroxyl group, a carboxyl group or a vinyl group, and said adhesive polyimide resin layer having a glass transition temperature of from 50 to 250° C. and a Young's modulus (storage modulus) at 250° C. of 10 5  Pa or more. 
     
     
       9. The laminate according to  claim 3 , wherein the adhesive polyimide resin has a peel strength retention of 50% or more, and wherein the peel strength retention is defined as a ratio (P 2 /P 1 ) of (A) the peel strength P 1  obtained by coating onto a substrate a siloxane polyimide precursor-containing resin solution in a stage prior to forming the adhesive polyimide resin, drying, heat-treating at 180° C. for 5 minutes, and thermocompression-bonding the resultant to an adherend, and (B) the peel strength P2 obtained by thermocompression-bonding the resultant to an adherend after further heat-treating the resultant at 270° C. for 5 minutes.